The invention relates to a locking device for (detachable) locking a displaceable motor vehicle part (in respect to the motor vehicle structure), which is lockable by means of the locking device within a displacement range in a respective rest position reached by displacement.
In the present case the displacement range of the motor vehicle part has to be understood as a range, in which the motor vehicle part is in each case lockable in different positions (optionally continuously variable). This displacement range does not necessarily have to comprise the complete possible range of motion of the motor vehicle part. The motor vehicle door can be, for instance only locked in a respective partially opened position obtained by displacing or pivoting, if—out from the closed position of the motor vehicle door—a certain pivot angle was scanned. Hereby an unintended braking should be avoided during a closing process of the motor vehicle door in the last part of the closing motion.
Said locking device comprises a braking device with at least two braking elements which interact in a braking manner in a respective rest position of the motor vehicle part, for instance laying against each other under conditions of static friction, for locking the motor vehicle part in a previously adopted position and which can be brought in a position without braking engagement during a displacement of the motor vehicle part so that they can be moved towards each other.
The displaceable motor vehicle part can be in particular a deflectable part of a motor vehicle, like for instance a motor vehicle door (side or tail gate door), storage flap, fuel tank flap or also an adjustable outside mirror.
The locking device should provide a possibility to be able to lock (removable) a displaceable motor vehicle part in a displacement range in a multitude of respective intermediate position such that unintended external effects like for instance a gust or an accidentally touching of the motor vehicle part does not lead to a further displacement of the motor vehicle part. Herewith a collision of the vehicle part with neighbouring motor vehicles, lamp posts or other obstacles shall be prevented. On the other side, the motor vehicle part (for instance for a further pivoting or a return) should be displaceable, if a person acts on the displaceable motor vehicle part (exerting a release force or a release moment) by overcoming the braking force or a herewith related braking moment existing in the rest position of the motor vehicle part.
The motor vehicle door should be for instance in each case lockable in a number of pivot positions between the completely locked position and the completely opened position such that an unattended acting on the motor vehicle door, for instance by a gust, does not lead to a change of the present (partly opened) position of the motor vehicle door. However, a vehicle driver or a passenger should be simultaneously able to bring a partially opened motor vehicle door by acting on it into the closed position or to open it further without a problem.
A locking device of the mentioned kind is for instance known from WO 2009/007700 A1, wherein the braking device is designed as friction brake comprising two friction elements movable towards each other, which lay against each other in a respective rest position of the motor vehicle part under conditions of static friction for locking the motor vehicle part and which are moved towards each other in case of a displacement of the motor vehicle part, whereby they slide against each other under sliding friction conditions.
For this kind of locking devices an unintended collision of the displaceable motor vehicle part with an obstacle located in the surrounding like for instance a further motor vehicle part, a roadside tree, a street lamp or such, can then not be avoided if an operating person actively moves the respective motor vehicle part towards said obstacle, perhaps since the obstacle was overlooked or the acting force onto the motor vehicle part was underestimated.